The study found around 5% of setts in Northern Ireland show signs of human interference. Evidence included digging indicative of badger baiting; sett entrances being blocked with soil, boulders and branches or being pumped full of slurry. The Institute for Global Food Security at Queen's collaborated with the University of Glasgow and the Agri-Food and Biosciences Institute in the research project, which was funded by the Wellcome Trust.

The new study, published in the scientific journal Natural Scientific Reports, focused on farmers who have acted outside the law in an effort to eradicate the disease.

Dr Neil Reid, lecturer in Conservation Biology at Queen's University, said: "The relationship between badger persecution and bovine TB in cattle could either be because persecuting badgers perturbs the population stimulating spread of the disease or farmers are more likely to persecute badgers if their livestock have previously had a TB breakdown. We can't say which way round the relationship is but we can say that persecuting badgers certainly does not lower TB risk in cattle, it is illegal and may make the situation worse."